package com.xd.common.util;

import lombok.extern.slf4j.Slf4j;

import java.io.*;
import java.util.List;
import java.util.Objects;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;


@Slf4j
public class CompressDownloadUtil {


    /**
     * 将多个文件压缩到指定输出流中
     *
     * @param files        需要压缩的文件列表
     * @param outputStream 压缩到指定的输出流
     * @author hongwei.lian
     * @date 2018年9月7日 下午3:11:59
     */
    public static void compressZip(List<File> files, OutputStream outputStream) {
        ZipOutputStream zipOutStream = null;
        try {
            //-- 包装成ZIP格式输出流
            zipOutStream = new ZipOutputStream(new BufferedOutputStream(outputStream));
            // -- 设置压缩方法
            zipOutStream.setMethod(ZipOutputStream.DEFLATED);
            //-- 将多文件循环写入压缩包
            for (int i = 0; i < files.size(); i++) {
                File file = files.get(i);
                FileInputStream filenputStream = new FileInputStream(file);
                byte[] data = new byte[(int) file.length()];
                filenputStream.read(data);
                //-- 添加ZipEntry，并ZipEntry中写入文件流，这里，加上i是防止要下载的文件有重名的导致下载失败
                zipOutStream.putNextEntry(new ZipEntry(i + file.getName()));
                zipOutStream.write(data);

                filenputStream.close();
                zipOutStream.closeEntry();
            }
        } catch (IOException e) {
            log.error("error,msg:{}", e.getMessage());
        } finally {
            try {
                if (Objects.nonNull(zipOutStream)) {
                    zipOutStream.flush();
                    zipOutStream.close();
                }
                if (Objects.nonNull(outputStream)) {
                    outputStream.close();
                }
            } catch (IOException e) {
                log.error("error,msg:{}", e.getMessage());
            }
        }
    }


    /**
     * 下载单个文件到本地
     *
     * @param localFileName 本地文件名称
     * @param is            源文件-输入流
     * @param fileName      源文件-文件名
     */
    public static void zipOneFile(String localFileName, InputStream is, String fileName) {
        ZipOutputStream zipOut = null;
        try {
            zipOut = new ZipOutputStream(new FileOutputStream(localFileName));
            zipOut.putNextEntry(new ZipEntry(fileName));
            //	输出文件
            int len = 0;
            byte[] buffer = new byte[1024];
            while ((len = is.read(buffer)) > 0) {
                zipOut.write(buffer, 0, len);
            }
        } catch (IOException e) {
            log.error("获取文件失败:{}", e.getMessage());
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    log.error("关闭流失败:{}", e.getMessage());
                }
            }
        }
    }


    /**
     * 压缩多个文件到本地
     *
     * @param localFileName 本地文件名
     * @param files         File文件集合
     */
    public static void zipFiles(String localFileName, List<File> files) {
        ZipOutputStream zipOut = null;
        try {
            zipOut = new ZipOutputStream(new FileOutputStream(localFileName));


            for (File file : files) {
                FileInputStream fis = null;
                try {
                    fis = new FileInputStream(file);
                    //  单个文件名称
                    zipOut.putNextEntry(new ZipEntry(file.getName()));

                    //	输出文件
                    int len = 0;
                    byte[] buffer = new byte[1024*8];
                    while ((len = fis.read(buffer)) > 0) {
                        zipOut.write(buffer, 0, len);
                    }
                } catch (Exception e) {
                    log.error("压缩文件失败:{}", e.getMessage());
                } finally {
                    if (fis != null) {
                        try {
                            fis.close();
                        } catch (IOException e) {
                            log.error("关闭流失败:{}", e.getMessage());
                        }
                    }
                }
            }
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        } finally {
            if (zipOut != null) {
                try {
                    zipOut.close();
                } catch (IOException e) {
                    log.error("关闭流失败:{}", e.getMessage());
                }
            }
        }
    }
}
